The goal of this project is to map and identify genes for syndromic and nonsyndromic forms of herditary deafness. Linkage analyses are being conducted using large pedigrees segregating non-syndromic or syndromic forms of deafness. If linkage to a known syndromic, DFNA (dominant) and DFNB (recessive) locus in large families is excluded, we initiate a genome-wide screen. This strategy has allowed us to map new deafness loci such as DFNA20, DFNA27, DFNA28 and DFNA36, DFNB29, DFNM1, DFNB29 and DFNB37. The chromosomal map locations of these novel deafness genes are then refined prior to initiating positional cloning strategies to identify the genes responsible for the hearing loss. Recently we have identified genes for DFNB6, DFNB12, DFNB23, DFNB37, DFNA28, Usher 1D and Usher 1F. Additional families with dominant and recessive modes of inheritance with profound congenital or progressive hearing loss are being ascertained with the goal of mapping and cloning additional novel genes that are necessary for hearing and/or maintenace of the auditory system. We are also asscertaining families, mapping loci and identifying genes for Usher syndrome. The defining clinical features of Usher syndrome are hearing loss and progressive retinopathy. For example, the genes for USH1D and USH1F were recently identified (CDH23 and PCDH15) by staff of the SHG/LMG.